Some of the biggest names in technology have been lavishing millions on Congress during the third quarter, according to government documents — at a time when they're under increasing regulatory scrutiny from Washington.

The legislation require disclaimers and disclosures to the Federal Election Commission for online political ads. Platforms with 50 million or more unique monthly users would have to keep a public database of political ads, and the companies would have to make "reasonable" efforts to prevent foreign nations from interfering with U.S. elections through ads.